Wheel carriage assemblies are typically used to facilitate movement of (and/or guide in three-dimensional space) items such as pieces of fabric or other flexible material, panels, louvers, doors, and so forth. For example, a wheel carriage assembly may be utilized to move pieces of fabric along a guide track to cover a specific area. In a window roller shade application, a wheel carriage assembly often couples to a hembar which may be coupled to a piece of fabric. In response to the hembar moving in a direction, the wheel carriage assembly moves as well, allowing the fabric to move and cover the desired area. However, the area that is desired to be covered may not be of a uniform shape, and may be positioned at an angle or different angles with respect to horizontal and vertical planes in a particular three-dimensional space. For example, a covering may be utilized for a triangular window or a semi-circular window over a doorway, or a window that is a truncated triangle and is both sloping and tilted (i.e., where the top and bottom are not in the same plane, and the sidewalls are not in parallel).
In prior approaches, when a window shade having a hembar coupled to a wheel carriage assembly at either end is pulled, the hembar at the end of the fabric may not move freely, its position dependent on the position, sliding resistance, etc. of the various wheel carriage assemblies attached to the hembar. Additionally, the maneuvering of the hembar may place a large weight load on specific wheels contained within the wheel carriage assembly (for example, wheels closest to a hembar coupling point). This imbalance of the load can cause particular wheels in the wheel carriage assembly to wear at faster rate than their counterparts.
Additionally, in various prior approaches, wheel connecting devices used to connect the wheels to the rest of the wheel carriage assembly may be inserted through the center of the wheel. Without more, the wheel connecting devices continually experience sliding friction and/or binding while the wheel carriage assembly is pulled along the guide track. This type of friction is hard on the wheel carriage assembly, along the wheel connecting devices in particular, and can cause a high degree of wear as well, especially in applications where the guide track is not parallel to the direction of movement of the hembar and fabric. Accordingly, improved systems and methods for facilitating movement of a hembar are desirable.